對于關(guān)鍵碼序列{38,64,52,15,73,40,48,55,26,12},用篩選法建最小值堆,若一旦發(fā)現(xiàn)逆序?qū)瓦M(jìn)行交換,共需要交換元素多少次? For the key value sequence {38,64,52,15,73,40,48,55,26,12}, use the screening method to constuct a minimum heap, if we exchange them when we find reversed order, then how many times should we exchange them?